This invention relates to apparatus for filling and emptying water beds.
Water beds have been used for many years as an improved, buoyant, supporting mattress capable of distributing support to adapt to the weight and conform to the shape of all portions of the human body. Typically, water bed mattresses consist of a flexible, hollow plastic shell which is collapsible and is shaped substantially similar to a conventional mattress when filled with water. Very high quality mattresses have been made for years, typically of vinyl plastics or similar material, and such mattresses are capable of providing many years of excellent service. However, substantial problems have persisted for many years in the method and apparatus used for filling and draining water beds.
Typically, a water bed mattress has an opening in the upper surface through which water can be added or withdraw. To add water (or other additives such as fungicides), one connects a hose to the outlet of the opening and fills the mattress to the desired capacity. While apparently a simple operation, this can lead to undesired results. For example, if the water supply suddenly fails, a partial vacuum on the water line may be created which draws the contents out of the mattress and into municipal water lines. This can be a potential health hazard where fungicides or other chemicals in the mattress are drawn into the water lines.
Problems are also encountered in draining a water bed mattress, for example, to move it, repair it, or to put in fresh water or fungicide. To drain the mattress, it is necessary to withdraw the contents, typically by pumping the liquid out of the opening in the upper surface. The types of apparatus for achieving this have been inconvenient and unwieldy. Moreover, since water beds are typically drained only at infrequent intervals, perhaps even several years, it has been necessary to store the drainage pump and other associated equipment for long periods between use, with the attendant risk of misplacing one or more components and the necessity for maintaining external storage space.
Typically, water bed mattresses are drained by use of a venturi type pump such as that shown, for example, in U.S. Pat. No. 3,456,270, to Weinstein, et al. Such pumps may consist of a T-shaped arrangement wherein one end of the cross arm of the T is connected to a water faucet, and the other end extends downwardly to a sink. Water is injected at a high flow rate through the vertically positioned cross arm of the T, causing a siphoning effect to draw a partial vacuum on the leg of the T. A hose is connected to the leg of the T and then inserted in the opening in the top of a water bed mattress, or attached to the outlet of the mattress. The partial vacuum gradually draws the liquid contents from the mattress and allows the mattress to collapse as it is emptied.
In typical use, water beds are not located near a faucet and sink, or other drain, and it is necessary to convey the contents of the mattress a substantial distance through the hose of the sink. Thus, very high vacuums must be drawn to effectuate the removal. Consequently, it is often necessary to pump the contents for substantial periods, often in excess of 2 hours to drain a normal size water bed. Further, it is necessary to use a hose or conduit which is flexible enough to bend around corners yet of high radial rigidity, since nonrigid conduits will collapse under vacuums and prevent the withdrawal of the liquid. Typically, a bulky and unwieldy garden-type hose is used for this purpose. Moreover, as previously noted, storage space must be provided for keeping the pump and bulky hose perhaps for many years, until the mattress is drained again.
It is an object of the present invention to overcome these problems of the prior art, and to provide a means and apparatus for rapidly, safely, and efficiently draining and filling water bed mattresses, and to provide apparatus which can be stored in minimal space. In its preferred embodiments, it is an object of the present invention to provide apparatus which can be integrally stored within the mattress itself.